In tests for various electronic instruments and electrical instruments, waveforms of electric signals are generally measured. In this waveform measurement, there are cases where a waveform called ringing needs to be measured. Ringing is an undulating waveform caused in such a case where a signal, such as a square wave, which changes steeply, passes through an electric network. Ringing is caused by inductance of an interconnection, a shortage of a transmission bandwidth, and the like.
FIG. 10 is a view showing an example of a waveform including ringing.
As shown in FIG. 10, in a waveform containing ringing, an overshoot or an undershoot occurs in an edge portion of the waveform including ringing, and the waveform undulates.
The waveform of an electric signal is measured using a measuring device such as an oscilloscope. An overshoot (αin FIG. 10) and an undershoot of a signal can be measured with an ordinary measuring device of this type. However, the peak-to-peak amplitude (β in FIG. 10) of ringing (e.g., see TDS3000B Series User Manual, P 3-44 to P 3-46, Tektronix, hereinafter referred to as Non-Patent Document 1) is not measured with the ordinary measuring device.
As described above, in a case where ringing is measured in the measurement of the waveform of an electric signal, an overshoot and an undershoot of the signal can be measured with a conventional measuring device. However, the peak-to-peak amplitude of the ringing cannot be measured with the conventional measuring device. Accordingly, even in a case where the peak-to-peak amplitude of this ringing is desired to be measured, such as a case where an attempt is made to analyze a cause of the ringing, such a measurement cannot be performed with the conventional measuring device.